(a) Field of the Invention
The present invention relates to a mobile communication system, and in particular, to an uplink framing method and apparatus.
(b) Description of the Related Art
In a portable Internet system, which is one type of mobile communication system, when a long frame period of 8 ms or more is transmitted, it is necessary to ensure a sufficient amount of time to allow a medium access control (MAC) scheduler to generate and transmit an uplink packet data unit (PDU) of the selected frame. Accordingly, all of the functions of a system that transmits a frame are implemented by software (SW) due to implementation complexity and to further function improvement flexibility.
As the frame period becomes longer, the round trip time (RTT) of a transport control protocol (TCP) as an upper layer becomes increased. Then, the TCP layer recognizes that congestion occurs in the system. Accordingly, a congestion control algorithm is performed, and thus only slow data transmission is possible.
Meanwhile, all of the functions of the system may be implemented by hardware (HW). To fast transmit a frame period of 5 ms or more, an uplink scheduler needs to generate and transmit the uplink PDU during an uplink period defined by a base station.
When all of the functions of the system are implemented by hardware, implementation complexity and debugging complexity are increased. Particularly, when a plurality of constituent elements are connected to the system, it is difficult to implement a memory management routine by hardware. In addition, it is difficult to apply a new function or algorithm to the system.
The functions of the system may be implemented by hardware and software. To support traffic session connection between a terminal and a base station, a plurality of external memories are needed. Accordingly, it is difficult to implement an interface between a field-programmable gate array (FPGA) and the external memories. Further, an external interface delay additionally occurs.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.